AAA screening recommendation comes up short

February 11, 2005

Men between the ages of 65 and 75 who have ever smoked now have the government’s stamp of approval for a one-time abdominal aortic aneurysm ultrasound screening. Interventional radiologists and vascular surgeons praise the move but want women and nonsmoking men to have the same imprimatur.

Men between the ages of 65 and 75 who have ever smoked now have the government's stamp of approval for a one-time abdominal aortic aneurysm ultrasound screening. Interventional radiologists and vascular surgeons praise the move but want women and nonsmoking men to have the same imprimatur.

In 1996, the U.S. Preventive Services Task Force (USPSTF) found insufficient evidence to advise for or against routine screening for AAA in any asymptomatic adult. Several population-based clinical trials have been completed since then, however, and the USPSTF has revisited the issue.

The new data revealed that screening in older men with a history of smoking reduces AAA-related mortality, although the total number of deaths from all causes was not significantly reduced.

The evidence was fair that screening can improve health outcomes for men who have never smoked, but the balance of benefit and harm was too close to justify a general recommendation, according to the report (Ann Intern Med 2005;142:203-211). The USPSTF found fair evidence that screening is ineffective in women and recommended against the practice.

In a letter to the task force after reviewing a draft of the report, the Society of Interventional Radiology asked that the recommendation for screening include all male nonsmokers and women with a positive family history of AAA. It also asked that the task force make no recommendation regarding women without family histories, rather than issue a fiat against the practice.

A four-year study of the SIR's national Legs For Life program, which offers free screenings, found one in four participants at risk for AAA. One in 20 had an aneurysm. More than 46,000 people have been screened for AAA in the program, according to Dr. Katherine Krol, who presented the study at the 2004 SIR meeting.

"As a practitioner, it's hard to say that we're not going to screen women because we know we will pick up otherwise undetected aneurysms in them," said Krol, interventional radiology director for Corvasc, Indianapolis, IN.

The Society for Vascular Surgery recommends screeningfor all men aged 60 to 85 years, women aged 60 to 85 years with cardiovascular risk factors, and men and women older than 50 years with a family history of AAA. The exclusion of women and men who don't smoke may miss one-third of existing aneurysms, said Dr. William Flinn, vice chair of the American Vascular Association, a foundation of the Society for Vascular Surgery.

About 1% of the people screened annually in the American Vascular Association's free program have a AAA. Of these, 60% never smoked and 40% do not have hypertension. These people would go undiagnosed under the current recommendation, Flinn said.

"When you have the chance to eliminate a fatal disease, we think you should take it," he said.

From a public health and economic point of view, Dr. Barry T. Katzen, medical director of Baptist Cardiac & Vascular Institute in Miami, FL, agrees with the "men only" recommendation. He does, however, favor a broader application of screening to include all men over the age of 55, in particular nonsmokers with additional risks such as family history.

Medicare does not pay for preventive medicine unless Congress requires it, and the $400 scan is not reimbursable. That could change if advocates are successful on Capitol Hill. Last year, the National Aneurysm Alliance, a coalition of medical specialty societies, foundations, and industrial partners, worked to secure the passage of legislation to provide a one-time ultrasound screening for at-risk Medicare beneficiaries.

With the added weight of the task force recommendation, the group will redouble its efforts to gain passage of the SAAAVE bill (Screen Abdominal Aortic Aneurysms Very Efficiently) in the 109th Congress, Flinn said.

"We will insist the legislation include women at the highest risk," he said.

The American College of Radiology is currently drafting - in collaboration with the American Institute for Ultrasound in Medicine - a formal guideline for AAA screening. It will be up for approval at the ACR annual meeting in April. If approved, it will go into effect in October, according to an ACR spokesperson.

The full task force study is available online.

For more information from the Diagnostic Imaging archives:

CT and MR compete to visualize vessels

AAA screening project shows encouraging results

Imaging evaluates success of AAA repair

Emergency CT helps detect aortic disease